In the training of cardiologists, considerable emphasis is placed on learning proper precordial examination, and how to properly obtain and interpret electrocardiograms, echocardiograms, hemodynamics and contrast and radionuclide angiograms. In contrast, relatively little emphasis is placed on learning how to interpret "routine" radiographs of the chest. This report describes a simple technique to aid in the interpretation of the cardiac and aortic silhouette on chest roentgenogram. A 3x5 inch (7.6x12.7 mm) card is cut so that it is square 3x3 inches) (7.6x 7.6 mm). On the card, 4 equal-sized circles are drawn. The circle closest to the bottom of the card represents right ventricle (RV), the 1 to the right, right atrium (RA), the 1 toward the top of the card, left atrium (LA) and the 1 to the left, , left ventricle (LV). Between the RA and RV, of course, is the tricuspid valve (TV), and between the LA and LV, the mitral valve (MV). The aortic valve (AV) lies in the center surrounded by the circles representing each of the 4 cardiac chambers. The descending thoracic aorta (A) is located to the left of the mitral valve. The esophagus (E) is located between the LA and vertebral bodies. After these structures are drawn on the 3x3 inch card, the ends of a pipecleaning wick are placed through the aortic valve and descending aorta and secured by bending the wire on the back of the card. The wick then represents the ascending, transverse and proximal descending thoracic aorta. The bottom of the card represents the anterior chest wall, the right (R) side of the card, the right side of the chest, the top of the card, the posterior wall, and the left (L) edge of the card, the left lateral wall of the chest. The card can now be viewed from the front, left lateral position, left anterior oblique (LAO) position and from the right anterior oblique (RAO) position, simply by rotating the card.